This invention relates to manual hand tools and more particularly to manual ink applicators commonly used in screen printing.
Clothing such as T-shirts, sweatshirts and the like commonly have images and printing placed on the article by a process called screen printing. Generally the process is done manually or automatically on screen printing machines. In either the manual or automatic process there is a screen firmly held slightly above the article of clothing. A flood bar is placed in contact with the screen and passed over the screen, spreading ink over the screen surface. Next a print squeegee is moved across the surface of the screen and a downward pressure is applied, which forces printing ink through the screen and onto the material that is to receive the image.
The manual screen printing process has some advantages over the automatic printers. They are relatively inexpensive to purchase and operate. They are also energy and space efficient. The manual process is particularly well suited for small runs and test runs prior to setting up the automatic machines.
However, there are several problems that arise when using manual printing machines that are not present when using an automatic machine. First, the manual printing machines operate slowly. One reason is that the squeegee requires a substantial amount of pressure applied to it to force the ink through the screen. The operator must flood the ink consistently and then apply adequate pressure to print an article. In order to get the density, opacity or finish desired, and depending on the pressure applied, it may require multiple passes of the squeegee. Further many plastisol ink colors have a high tack level and require considerable force to transfer the ink cleanly through the mesh of the screen. Second, when applying high-density inks, the same problems as stated above are present and a sufficiently high and constant pressure is required for clean printing. A substantial force is required to be applied to the squeegee throughout the printing stroke. Most operators cannot withstand this effort for making multiple prints as fatigue sets in. The results of manual screen printing using a conventional squeegee are inconsistency and diminishing productivity. Furthermore, job related injuries such as carpal tunnel syndrome often result.
Applicant""s invention provides a manual tool that applies the required force necessary to print with today""s inks. The tool transfers the force from the user""s arm and body to the squeegee instead of applying the force from the user""s wrists and fingers to the squeegee. Thus, greater force can be applied to the squeegee and fatigue to the user""s wrists, hands and fingers is minimized.
Applicant""s device has a pair of opposed shuttle blocks positioned on either side of the screen printing apparatus. Each shuttle block has a pivoting bracket mounted on it. A squeegee is mounted between and to the pivoting brackets. There is a shaft having one end connected to the squeegee holder. Near the other end of the shaft is a brace through which the user places his or her arm. The user grasps a handle on the shaft so that when the user grasps the handle and the brace encompasses the user""s arm, the shaft and the user""s arm are aligned. The user applies a force to the squeegee through the handle and shaft for spreading the ink and for printing. In a first position, the pivoting bracket and squeegee assume an orientation to spread or flood the ink on the screen and in a second position in which the brackets are pivoted, the squeegee assumes an orientation for printing. The apparatus allows the user to apply greater forces with ease to the screen for printing, which minimizes fatigue and improves printing.
Thus it is an object of the invention to provide a manual ink applicator that allows the user to apply greater forces to the squeegee than have previously been applied using the user""s hand and fingers.
Another object is to provide a manual ink applicator that places the squeegee in a first orientation to spread or flood the ink across the screen when moved in a first direction and places the squeegee in a second orientation to print when moved in the opposite direction. Related to this object is the object of mounting the squeegee on a pivoting bracket arrangement that allows the squeegee to move from the first orientation to the second orientation by means of the pivoting bracket.
Still another object is the object of providing a manual ink applicator for screen printing in which the force from the user is transferred to the squeegee through the applicator without the user grasping the squeegee by the user""s hands to apply the printing force. A related object is the object of providing a manual ink applicator in which the applicator has a handle that is grasped by the user and a brace that encompasses the user""s arm to align the applicator with the user""s arm. An advantage of this apparatus is to efficiently transfer the force from the user to the squeegee.
Yet another object is to provide a squeegee that operates as a flood bar in one direction and a pressure applying squeegee in the other direction and in which the squeegee is raised above the screen when changing directions so that it is raised up and passes over the ink when changing directions.
These and other objects and advantages will be apparent from reading the Description of the Drawings and Description of the Preferred Embodiment.